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Jun 08, 2009

Kerengga - Our Organic Partners

Sceptics say, organic durians, sure?  How do you handle weevils that just love durians and can easily infest 40% of your fruits?  Or what about borers that kill the trees in weeks after you have lovingly taken care of the trees for years?  And squirrels, they love the durians, so what do you do, kill them?

Well, we have a few hundred durian and mango trees and we will tell you it's almost impossible (the labour costs will be too high) if not for our "friendly" neighbourhood kerengga ( weaver ants, or oecophylla smaragdina )

carnivorous ants.JPG

Gang of carnivorous kerengga attacking a piece of meat. Meat is used to establish a colony in a new tree.


kerengga nests.JPG

Kerengga nests the size of large durians.


dead tree from borers.JPG

A tree killed by borers.

fresh borer hole oozing sap.JPGA borer hole that’s still active and oozing sap.

dry borer hole after kerengga.JPG

 A borer hole that's dry after kerengga cleaned out the borers 






Highway of raffia strings for the weaver ants to form a colony of 20 to 30 trees around one central tree.

superhighway.JPGA 20 meter long raffia highway.  The ants learn to use it after two days ( with coaching from us of course).


using the highway.JPG

Using the highway


new nest.JPG

New weaver ant nests as they colonise a new tree.



Once the weaver ants colonise a tree, the borers are gone.  Weevil infested fruits and squirrel attacks are almost non-existent.  That gives us time to focus on the other major problem with durian trees – phytoptera attacks, for which sadly, we have no answer as yet.



Thanks for the great description!

I was wondering how weaver ants were actually encouraged. Do you plant any Sea Hibiscus (Hibiscus tiliceaus; BM Baru Baru/Baru Laut) or Great Morinda (Morinda citrifolia; BM Mengkudu ) too, and if so, is it effective?
(as mentioned here http://www.naturia.per.sg/buloh/inverts/weaver_ants.htm)

I was discussing your weaver ants with some friends in Bangsar last night, and one mentioned she'd observed weaver ants marching along the net of vines in the mangrove swamp (and her body if she stood still too long) - a great example of mimiking nature to make use of biological resources.

Posted by: Cath | Jun 15, 2009

Hi Cath,
You encourage the ants with pieces of meat and you have to have a balance to maintain a viable population for the fruiting seasons.

BTW the pair of monkeys that u were concerned about being caged?, they have finally learnt to live on their own and has not returned for a month now. We rescued them from some villager who kept them since babies in tiny cages.

Felicity called.

Posted by: HS | Jun 17, 2009

The comments are closed.